Field
The present invention relates to apparatuses, methods, systems, computer programs, computer program products and computer-readable media usable for conducting device-to-device communication in a communication network.
Background Art
The following description of background art may include insights, discoveries, understandings or disclosures, or associations, together with disclosures not known to the relevant art prior, to at least some examples of embodiments of the present invention but provided by the invention. Some such contributions of the invention may be specifically pointed out below, whereas other such contributions of the invention will be apparent from their context.
The following meanings for the abbreviations used in this specification apply:
ARQ: automatic repeat request
CH: cluster head
CPU: central processing unit
D2D: device-to-device
E-UTRAN: evolved UMTS radio access network
eNB: evolved node B
HARQ: hybrid ARQ
HO: handover
ID: identifier
L1: layer 1 (physical layer)
L2: layer 2 (media access control layer)
LTE: Long Term Evolution
LTE-A: LTE Advanced
M2M: machine-to-machine
PHY: physical layer
ProSe: proximity services
RAN: radio access network
UE: user equipment
UMTS: universal mobile telecommunication system
In the last years, an increasing extension of communication networks, e.g. of wire based communication networks, such as the Integrated Services Digital Network (ISDN), DSL, or wireless communication networks, such as the cdma2000 (code division multiple access) system, cellular 3rd generation (3G) and fourth generation (4G) communication networks like the Universal Mobile Telecommunications System (UMTS), enhanced communication networks based e.g. on LTE or LTE-A, cellular 2nd generation (2G) communication networks like the Global System for Mobile communications (GSM), the General Packet Radio System (GPRS), the Enhanced Data Rates for Global Evolution (EDGE), or other wireless communication system, such as the Wireless Local Area Network (WLAN), Bluetooth or Worldwide Interoperability for Microwave Access (WiMAX), took place all over the world.
Generally, for properly establishing and handling a communication connection between terminal devices such as a user device or user equipment (UE) and another communication network element or user device, a database, a server, host etc., one or more intermediate network elements such as communication network control elements, such as access points, base stations, control nodes, support nodes or service nodes are involved which may belong to different communication network.
So-called proximity based services (ProSe), which are also referred to as D2D (or machine-to-machine (M2M)) communications are expected to become a feature in future communications networks. ProSe are designed to provide an option to offload (cellular) communications system, reduce battery consumption and increase bit-rate, and hence also enable new services. ProSe is also an important part of communication requirements for Public Safety usage.
D2D communications may be implemented, for example, as an underlay to cellular networks, such as an LTE-Advanced network. One intention of D2D communication is to enable direct communication connection establishment between communication devices such as UEs, wherein “direct” means without involvement of an intermediate network element in between. D2D communication may be performed under a continuous network management and control and/or in cases where the communication devices are out of coverage of the cellular network.